Maric Irina, Robyn Jamie, Metcalfe Dean D, Fay Michael P, Carter Melody, Wilson Todd, Fu Weiming, Stoddard Jennifer, Scott Linda, Hartsell Marilyn, Kirshenbaum Arnold, Akin Cem, Nutman Thomas B, Noel Pierre, Klion Amy D
Department of Laboratory Medicine, Clinical Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
J Allergy Clin Immunol. 2007 Sep;120(3):680-7. doi: 10.1016/j.jaci.2007.05.024. Epub 2007 Jul 12.
The broad and overlapping clinical manifestations of D816V KIT-associated systemic mastocytosis with eosinophilia and FIP1L1/PDGFRA-associated chronic eosinophilic leukemia (CEL), coupled with the increase in activated eosinophils and mast cells seen in both disorders, have led to confusion in the nomenclature. It is of paramount importance, however, to distinguish between these 2 groups of patients because of differences in clinical sequelae, prognoses, and selection of treatment.
We thus sought to identify clinical and laboratory features that could be used to distinguish these 2 diagnoses.
We compared 12 patients with D816V-positive systemic mastocytosis with eosinophilia with 17 patients with FIP1L1/PDGFRA-positive CEL. Distinguishing features were used to create a risk factor scoring system.
This system correctly classified 16 of 17 FIP1L1/PDGFRA-positive patients with CEL and all 12 patients with systemic mastocytosis with eosinophilia. Thirty-four FIP1L1/PDGFRA-positive patients described in the literature were also classified using this system, and although a complete set of data was not available for any of the historical patients, 21 were correctly classified.
These results reinforce the hypothesis that the FIP1L1/PDGFRA gene fusion and D816V-KIT mutation cause distinct clinical syndromes.
This novel diagnostic approach should prove helpful in clinical practice in the evaluation of patients with increased mast cells and peripheral eosinophilia.
D816V KIT相关的伴有嗜酸性粒细胞增多的系统性肥大细胞增多症与FIP1L1/PDGFRA相关的慢性嗜酸性粒细胞白血病（CEL）具有广泛且重叠的临床表现，再加上在这两种疾病中均可见活化嗜酸性粒细胞和肥大细胞增多，导致了命名上的混乱。然而，由于临床后遗症、预后及治疗选择存在差异，区分这两组患者至关重要。
因此，我们试图确定可用于区分这两种诊断的临床和实验室特征。
我们将12例D816V阳性的伴有嗜酸性粒细胞增多的系统性肥大细胞增多症患者与17例FIP1L1/PDGFRA阳性的CEL患者进行了比较。利用鉴别特征创建了一个危险因素评分系统。
该系统正确分类了17例FIP1L1/PDGFRA阳性的CEL患者中的16例以及所有12例伴有嗜酸性粒细胞增多的系统性肥大细胞增多症患者。文献中描述的34例FIP1L1/PDGFRA阳性患者也使用该系统进行了分类，尽管历史患者均无完整数据集，但21例被正确分类。
这些结果强化了FIP1L1/PDGFRA基因融合和D816V-KIT突变导致不同临床综合征的假说。
这种新的诊断方法在临床实践中评估肥大细胞增多和外周嗜酸性粒细胞增多的患者时应会有所帮助。
